KVPY SX SB Exam 05-Nov-2017 Question Paper

One mole of an ideal monatomic gas undergoes the following four reversible processes :
Step1 : It is first compressed adiabatically fromvolume ${\mathit{V}}_1$ to 1m${}^3$
Step 2 : then expanded isothermally to volume10 m${}^3$
Step 3 : then expanded adiabatically to volume${\mathit{V}}_3$.
Step 4 : then compressed isothermally to volume ${\mathit{V}}_1$.
If the efficiency of the above cycle is 3/4 then ${\mathit{V}}_1$ is,